Field of the Invention
The present invention pertains to motor vehicles. More specifically, the present invention pertains to those having only three wheels.
Description of the Related Art
Typical road use, highway speed, three wheeled vehicles consist of the following layout types:                Type-1—Two wheels in the rear of the vehicle with the rear wheel driven.        Type 2—Two wheels in the front of the vehicle with the rear wheel driven. Variations of this are:                    (A) Straddle type seating where the body or engine is straddled by the passenger, whether the engine is directly underneath, forward, or rearward of the driver.            (B) Traditional seating with engine in front of the passenger seat.            (C) Traditional seating with engine behind the passenger seat.                        Type 3—Two wheels in the front of the vehicle with the front wheels driven. Variations of this are:                    (A) Straddle type seating where the body or engine is straddled by the passenger, whether the engine is directly underneath, forward, or rearward of the driver.            (B) Traditional seating with the engine in front of the passenger seat.            (C) Traditional seating with engine behind the front of passenger seat.                            (1) Rear wheel steering.                (2) Front wheel steering. This vehicle type is the present invention.                                                
Three wheeled vehicles with two rear wheels, Type (1), suffer from detrimental stability problems when turning, and even more serious stability issues when braking while turning. This is a critical need, as maximum stability is required in emergency situations. It is very common for vehicles of this type to ‘tip over’ during more extreme maneuvers.
Three wheeled vehicles with a single rear wheel which is also the driven wheel, Type (2), have traction problems due to the power being driven through a single wheel. Loss of traction causes the driver to quickly lose control of the vehicle since there is no directional control. This can be especially dangerous when the vehicle is in a turn and the rear wheel loses traction. The loss of traction is compounded by the combination of lateral forces on the rear wheel from the turn, the forward forces from acceleration, and changes in contact pressure due to uneven road surfaces.
Three wheeled vehicles with two front driven wheels and the engine forward of the passenger seat, Type (3B), suffer from a broad variation in center of gravity as a result of varied passenger loading. The seated position requires legroom for the passenger, and pushes the engine farther away from the center of gravity of the driver. Not only does this impact vehicle dynamics while in motion, but it also brings about the larger concern of varying passenger loads based on the size of person(s), (especially if there are two seats), which changes the front to rear center of gravity for the vehicle as a whole. The inconsistent passenger load causes large variations of weight on the single rear wheel which dramatically changes the vehicle's dynamics, resulting in an inconsistent driving experience. This is of most concern during hard cornering, or situations involving wet or loose gravel roads where the traction of the rear wheel is reduced causing the vehicle to react differently due to the change in loading. Even the most experienced drivers may be challenged by the radical change in vehicle dynamics
Vehicles with straddle type seating, Type (2A) and (3B) provide certain advantages, however they do not provide the comfort and safety of traditional seating.
Each of the layout types defined above could incorporate front wheel or rear wheel steering as further layout sub-types, as depicted under Type (3C). Vehicles with primary steering provided through the rear wheels are generally less stable at higher speeds, causing additional stability concerns with a three wheeled vehicle.